1. Field of the Invention
The present invention relates to an ESD protection device for protecting a semiconductor apparatus or other suitable apparatus, etc. from electrostatic discharge failures, and more particularly, relates to an ESD protection device including at least a pair of opposed electrodes arranged to oppose each other on a ceramic base material, and a discharge auxiliary electrode film arranged to cover the opposed electrodes partially and cover a space between the opposed electrodes.
2. Description of the Related Art
In recent years, for the use of commercial-off-the-shelf appliances, there has been a tendency to increase the frequency of inserting and removing cables as input-output interfaces, and static electricity is likely to be applied to input-output connector areas. In addition, miniaturization in design rule with increases in signal frequency has made it difficult to create paths, and LSI itself has been very sensitive to static electricity.
Therefore, ESD protection devices have been used widely for protecting semiconductor apparatuses such as LSI and other apparatuses from electrostatic discharge (ESD).
As this type of ESD protection device, a component for countermeasure against static electricity has been proposed which includes at least two opposed electrodes 52a and 52b arranged so as to be opposed to each other on a ceramic base material 51, and a static electricity protective material layer 53 arranged so as to cover the opposed electrodes 52a and 52b partially and cover the space between the opposed electrodes, as shown in FIG. 10 (see Japanese Patent Application Laid-Open No. 2007-265713). It is to be noted that in this component for providing a countermeasure against static electricity, the static electricity protective material layer 53 is formed by using a static electricity protective material paste including at least metallic particles with a passive layer formed on the surfaces thereof and a resin, which is prepared by kneading the metallic particles and the resin.
In addition, the component for providing a countermeasure against static electricity in FIG. 10 further includes an intermediate layer 54 and a protective layer 55.
Incidentally, in the case of the component for providing a countermeasure against static electricity in Japanese Patent Application Laid-Open No. 2007-265713, the static electricity protective material layer includes the resin therein. Thus, the component has a limitation (critical PVC) in the ratio of the metallic particles in the static electricity protective material layer, and has a limitation in its ability to lower the discharge starting voltage or the lowering of the peak voltage.
In addition, the resin used for isolating the metallic particles from each other essentially does not have necessarily sufficient heat resistance and oxidation resistance. Thus, there is a problem that the resin is degraded thus causing performance degradation when static electricity is applied repeatedly.